Setting device of a thread grinding machine



April 24, 1962 K. H. SCHULTZE SETTING DEVICE OF A THREAD GRINDING MACHINE 5 Sheets-Sheet 1 Filed Sept. 4, 1958 Inventor? KURT H. SGHULF'ZE April 24, 1962 K. H. SCHULTZE 3,030,741

SETTING DEVICE OF A THREAD GRINDING MACHINE Filed Sept. 4, 1958 5 Sheets-Sheet 2 .lll l W jm/emon' EUR-1- H. SGHULTZEL April 1952 K. H. SCHULTZE 3,030,741

SETTING DEVICE OF A THREAD GRINDING MACHINE Filed Sept. 4, 1958 5 Sheets-Sheet 3 Inventor KURT H. SLHULTZE United States Patent SETTING DEVICE OF A THREAD GRINDING MACHINE Kurt H. Schultze, Berlin-Froimau, Germany, assignor to Herbert Lindner G.m.b.H., Berlin-Wittenau, Germany Filed Sept. 4, 1958, Ser. No. 758,935 Claims priority, application Germany Sept. 14, 1957 3 Claims. (Cl. 51-165) This invention relates in general to a thread grinding machine and in particular to an improved adjusting and setting device for a thread grinding machine in which a single adjusting wheel is employed for alternately adjusting or setting the dressing tool or workpiece with respect to the grinding wheel.

In thread grinding machines the dressing tool for dressing or truing the grinding wheel is generally adjustable by means of a separate spindle and wheel. in the more recent developments of the art, a single axle and wheel is used for setting both the dressing tool and the workpiece with respect to the grinding wheel. In this type of device, however, the adjusting wheel has to be turned alternately in one direction and then in the other for moving the grinding wheel respectively toward the workpiece and dressing tool. It is difiicult for a wo-rlcman to properly set the grinding wheel with respect to the workpiece after the grinding Wheel has been dressed. This becomes obvious when one considers that the setting for a particul at run of the grinding wheel is usually preset on the index drum by means of a lug cam connected to the graduated ring of the index drum. A zero setting has to be predetermined for dressing of the grinding wheel, as well as for the grinding of the workpiece. After a particular zero setting has been determined on the graduated ring a cut setting is added. The determination of the zero setting before the cutting is relatively easy when employing a roller type dressing tool, but is both costly and time consuming when a diamond dressing tool is used. In the latter case, thedressing of the grinding wheel is a delicate operation, since both wheel and diamond tool may be easily damaged. -In order to avoid excess wear or damage to either the grinding wheel or diamond dressing tool, the cutting contact between the diamond and grinding wheel must be gradual. Hence the zero setting for a diamond casing tool can only be obtained by cautiously manipulating the setting device until the diamond is in minimal contact with the grinding wheel. The grinding wheel is then slowly advanced toward the dressing tool, either mechanically (not shown) or manually, until the wheel is sufficiently dressed. The zero setting is then obtained by moving the wheel toward the workpiece, taking the reduction of diameter due to dressing into consideration. After this zero setting is obtained, the cut setting can be added on a graduated ring.

It is therefore an object of the present invention to provide a simplified and economical setting method in a thread grinding machine for setting the dressing tool or the workpiece with respect to the grinding wheel.

It is another object of the present invention to provide an index drum in a thread grinding machine which can set both the workpiece and dressing tool with respect to the grinding wheel and by means of which the grinding Wheel may be dressed and a new zero setting may be established simultaneously.

These and other objects may be achieved by providing the index drum with two graduated rings to each of which a lug cam is connected and which projects from the circumference of the ring. The graduated rings are indepently turnable by means of a setting hand wheel. Furthermore, the hand wheel is "provided with two pairs of clamping means for independently fixing the graduated 3,030,741 Patented Apr. 24, 1962 rings to the hand wheel, after a desired setting is indicated on therespective scale of the graduated rings. The two scales of the graduated'rings are divided into a suitable number of units which are readable in opposite direction to each other.

In order to facilitate the operation of the index drum, a swingable lever is attached to the carriage of the grinding machine. This lever can alternately engage the respective lug cams of the two graduated rings by swinging the lever to one side or the other. Furthermore, the lever can also be positioned in an inoperative position, that is a position in which both graduated rings can be turned by means of the hand wheel without engaging the lever with their respective lug cams.

When dressing of the wheel is required, the two pairs of clamping means are loosened and the graduated rings are turned in opposite directions until the required settings are located on the respective graduated scales of the rings. The clamping bolts are tightened again. It should be noted that the setting on the graduated scale for the workpiece must take into consideration the setting on the graduated scale for the dressing tool which has reduced the diameter of the grinding wheel (therefore, the grinding wheel carrier would have to move twice the distance to return to its original position). The swingable lever is then manually inclined to engage the lug cam of the graduated ring associated with the dressing tool. The handwheel is slowly turned until the lug cam engages the lever. The lever is then manually inclined to engage the lug cam of the graduated ring associated with the workpiece. The handwheel is then slowly turned in an opposite direction until the lug cam engages the other side of the lever.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the description of specific embodimen-ts when read in connection with the accompanying drawings, in which:

FIG. 1 shows a thread grinding machine in which the setting device of the present invention is incorporated;

FIG. 1a is a partial showing, similar to FIG. 1, of a grinding machine equipped with a diamond dressing tool;

FIG. 2 is an enlarged transverse-sectional View of the setting device indicated in FIG. 1;

FIG. 3 is an end elevation partly broken away of the setting device indicated in FIG. 1;

FIG. 4 is a detached fragmentary side elevation with a portion broken away, similar to FIG. 3 but showing the lever in operative contact with one of the lug cams; and

FIG. 5 is a developed view of a portion of the graduated rings.

With reference to the drawings, the invention is illustrated as being incorporated in a thread grinding ma- China. A grinding wheel 1 is provided with the usual thread profile along its circumference. The wheel is rotatably supported by a carriage 2 and is driven by an electrical motor or other similar means (not shown). At the front part of the machine a workpiece 5 is rotatably supported by a slidable workpiece holder 4. The workpiece 5 may also be driven by an electric motor or similar means (not shown). A. truing or dressing device 6 is supported behind the grinding wheel 1 (at the rear part of the machine). The dressing device 6 comprises a dressing tool which is illustrated in FIG. 1 as a roller or drum 7, but may also consist of a diamond dressing tool 7a as illustrated in FIG. 1a.

A setting spindle 8 is turnably supported by the machine and is operatively connected to carriage 2 by means 3 of a threaded connection. plified view of a part of the setting mechanism. The setting of the machine is accomplished by manually turning a handwheel 9 which is attached to a drum index 10.

Two independently graduated rings 11 and 12 are rotatably mounted on the index drum 10. Both of these rings are provided with milled rim portions. Furthermore two lug cams 13 and 14 are respectively secured to the outer peripheries of rings 11 and 12. We screws 15 and 16 are threadably mounted in the end face of the index drum 10. These screws have conically shaped ends 17 and 17'. Screw 16 bears against a pair of inclined surfaces 18, 19, located respectively at the inner ends of apair of clamping bolts 20, 21. By threadably moving the conically shaped end 17 of screw 16 against the inclined surfaces 18 and 19, the pair of clamping bolts 20 and 21 is forced apart into frictional holding contact with the inner rim portion of the graduated ring 12, thereby fixedly holding the ring 12 with respect to the index drum 10. Similarly the conically shaped end 17' of screw 15 can actuate a pair of clamping bolts (not shown) to fixedly hold the ring 11 with respect to the index drum 10. The heads of the screws 15 and 16 can be differentiated by either painting them in different colors or imparting to them a difierent serrated or knurled finish. The graduated rings 11 and 12 can be similarly differentiated.

A swingable substantially inverted T-shaped stop lever 22, having two arms, each having a stop edge 23 and 24 respectively and a central handle 25, is pivotally mounted on the carriage of the machine, and hence is swingable about its axis 22. By manually turning the lever towards the left by means of the handle 25, the stop edge 24 will engage the lug cam 14 affixed to the graduated ring 12. The stop edge 23 can similarly be moved to engage lug cam 13 of the graduated ring 11. A spring biased index pin 27 is mounted along the axis 22 of the swingable lever 22. This index pin 27 is arranged opposite a zero-position notch 28 located in the carriage of the machine and is biased into the notch by a spring 26 of the index pin 27 when the stop lever is in the zero position. In this position the stop edges 23 and 24 are in a neutral inoperative position in which they cannot engage their respective lug earns 13 and 14, thus permitting the graduated rings 11 and 12 to be freely rotated by means of the handwheel 9.

The device as described above may be operated in several ways. For instance, if a certain setting for an infeed is desired, the friction contact of the clamping bars 20 and 21 is discontinued by slightly withdrawing the screw '16. The graduated ring 12 is then manually turnable by holding the ring at its serrated portions (see FIG. By moving the ring a desired number of graduations a desired cutting run can be selected. After a run has been selected, the clamping bolts 20 and 21 are again made to bear against the inner run portion of the graduated ring 12 and fix the ring in the new setting position with respect to the index drum. The stop lever 22 is then put in the operative position by inclining it so that the stop edge 24 is placed in the path described by the lug cam 14. The run can begin by putting the spindle 8 in operative contact with handwheel 9. The handwheel 9 is then rotated to move the grinding wheel 1 against the workpiece 5.- Ihe rotation may continue until the cam lug 14 travels on the ring 12 completely around until a face comes against a stop edge 24 of the lever 22. Hence the run is completed when the lug cam 14, due to rotary movement of the index drum and ring 12, reaches the stop edges 24. It should be noted that the spindle 8 can operatively move the grinding wheel toward the workpiece 5 or the dressing tool 7 or 7a (FIGS. 1 or 1a) by alternatively turning in one direction or the other. Hence the device can also be used for first dressing the grinding wheel and thereafter resetting the amount of cutting feed on the graduated scale associated with the workpiece.

The spindle illustrates a sim- 4 The new zero position is then established when the lug cam reaches the other stop edge. This is accomplished by manually inclining stop lever 22 in the other position so that stop edge 23 is placed in the path described by the lug cam 13. The spindle 8 is now put in operative contact with the grinding wheel to move the wheel in the other direction toward the workpiece and therefore it must be rotated in an opposite direction to the first rotational direction. The spindle 8 and the index drum 10 carry the other graduated ring 11, which can be fixedly held with respect to the index drum, similarly to ring 12. Therefore, when the lug cam reaches the stop edge 23, the new zero position for the workpiece is automatically established. Of course, ring 11 may be the dressing tool ring and ring 12 the workpiece ring. In the latter case, the steps described above would similarly apply.

Both graduated rings may be divided into any desirable number of graduations. For instance, the rings may be divided into 200 graduations. One complete revolution usually corresponds to one millimeter of infeed of the machine. The stop levers stop edges 23 and 24 are selected to correspond to the respective zero readings of rings 11 and 12, which facilitates greatly the reading and setting of the device. A further dressing or cutting can be obtained by merely moving the corresponding ring as described above.

Since the rings are graduated in opposite directions (see FIG. 5), the selected settings can be read off the scales by always turning the rings in a direction away from the stop edges 23 and 24 of the stop lever (see FIG. 5). Since a special graduated ring is provided for the settingof the dressing tool and both graduated rings have lug cams which can independently make operative contact with the stop lever, the zero position of either the dressing tool or the workpiece can always be fixed with respect to the other. No undue manipulating of the setting handwheel or any computing of settings is necessary since the contact between the back-running lug cam and the stop edge always determines the new zero position.

The above described device greatly facilitates the servicing of the grinding machine. Furthermore, the possibility of making any errors in setting the device after dressing the grinding wheel are greatly reduced since by means of the device the distance between the workpiece axis and grinding wheel axis is automatically readjusted to compensate for the lessened diameter of the grinding wheel as it will exist after dressing.

A further advantage to consider is the fact that the scales of the rings can always be read in a positive sense (direction) from any newly established zero position.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of machine tools differing from the types described above.

While the invention has been illustrated and described as embodied in a setting device for a thread grinding machine, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed is:

1. In a thread grinding machine having a movable carriage, a rotating grinding wheel on said carriage, and a dressing and a workpiece station located on said machine on opposite sides of said grinding wheel, a setting and adjusting device comprising an infeed spindle rotatably mounted on said machine and rotatably and threadably connected to said carriage for moving said grinding wheel with respect to said stations, handwheel means axially connected to said spindle for selectively rotating the same in opposite directions so as to shift said carriage with said grinding wheel in a direction toward one of said stations, indicating means including two indicating rings rotatably and adjustable supported on said handwheel means and provided with scales graduated for readings in opposite directions, each of said rings being provided with a stop cam secured in directions opposite to each other at the outer periphery of said rings, clamping means adjustably mounted on said handwheel means for securing said indicating means in a fixed relative position with respect to said handwheel means for rotation therewith, and a swingable stop lever pivotally mounted on said machine adjacent the outer circumference of said rings and having two arms, each of said arms having a 20 stop edge positionable in the path of said stop cams for operatively engaging said stop cams and to stop thereby the rotating movement of the entire setting device and of said infeed spindle when said indicating means is fixedly supported by said handwheel means by the intermediary 25 of said clamping means.

2. In a thread grinding machine having a movable carriage, a rotating grinding wheel on said carriage, and

a dressing and a workpiece station located on said machine on opposite sides of said grinding wheel, a setting and adjusting device according to claim 1, wherein said clamping means includes first and second adjustable bolt means supported by said handwheel means for frictionally fixing the rotary movement of respective ones of said rings with respect to said handwheel means.

3. In a thread grinding machine having a movable carriage, a rotating grinding Wheel on said carriage, and a dressing and a workpiece station located on said machine on opposite sides of said grinding wheel, a setting and adjusting device according to claim 1, wherein said stop lever has a handle connected thereto for pivotally turning the same so that said stop edges may engage said stop cams, and further comprises positioning means adjustably mounted on said lever for fixedly positioning said lever in an inoperative position where said rings may turn without said stop cams engaging said stop edges.

References Cited in the file of this patent UNITED STATES PATENTS 1,514,352 Taylor et a1 Nov. 4, 1924 1,528,188 Frost Mar. 3, 1925 1,640,992 Hanson Aug. 30, 1927 2,469,077 Rickenmann May 3, 1949 FOREIGN PATENTS 264,786 Great Britain June 30, 1927 

